Phosphate selective composition and electrode

Abstract

Phosphate ion-sensitive composition and ion-selective electrode are disclosed incorporating an ionophore having the formula: R.sub.1 --X (a) or X--Z--X (b) wherein R 1 is H or a hydrophobic substituent, Z is a spacing unit and X is represented by the formula: ##STR1## wherein n=0 or 1 and R 2 and R' 2 are independently selected from the group consisting of CH 2 , C(O) or C(S).

What is claimed is: 
     
       1. A dibasic phosphate ion selective membrane electrode comprising: a) a conductive body member having an opening therein,   b) a membrane covering the opening comprising an ionophore represented by the following formulas:   R.sub.1 --X--                                              (1)        or   X--Z--X                                                    (2)        wherein R 1  is H or a hydrophobic substituent, Z is a spacing unit and X is represented by the formula: ##STR3##  wherein n=0 or 1 and R 2  and R' 2  are independently selected from the group consisting of CH 2 , C(O) or C(S),   c) a reference solution contained within said body member, and   d) a reference electrode disposed with said body member in contact with the reference solution.   
     
     
       2. The membrane electrode as defined in claim 1 wherein the membrane is a liquid membrane comprising the ionophore and a hydrophobic carrier solvent. 
     
     
       3. The membrane electrode as defined in claim 1 wherein the membrane comprises the ionophore in a supporting matrix. 
     
     
       4. A dibasic phosphate ion sensitive electrode having an ion-sensitive membrane comprising: a) an ionophore having the formula:   R.sub.1 --X                                                (1)       X--Z--X                                                    (2)        wherein R 1  is H or a hydrophobic substituent, Z is a spacing unit and X is represented by the formula: ##STR4##  wherein n=0 or 1 and R 2  and R' 2  are independently selected from the group consisting of CH 2 , C(O) or C(S).   
     
     
       5. The electrode as defined in claim 4 wherein the membrane comprises the ionophore in a supporting matrix. 
     
     
       6. The electrode of claim 4 wherein R 1  is substituted or unsubstituted alkyl or substituted or unsubstituted aryl.